This invention relates to a mounting arrangement for electrical plug-in components such as relays and sockets and particularly comprises an improvement over the arrangement shown in U.S. Pat. No. 3,790,915 for Mounting Arrangement for Electrical Plug-In Components, assigned to the assignee of the present invention.
In aircraft and other locations it becomes necessary to mount a number of plug-in components, such as relays, on a support such as a chassis or track where they engage mating sockets. This has been accomplished through the use of studs and nuts. Several difficulties are encountered through the use of such mounting arrangements. Space is severely limited within an aircraft which restricts access to the securing means. Expensive special tools frequently are necessary to allow installation and removal of the relays. Even so, crowded spacing may prohibit individual relay removal. For field maintenance such special tools may not be available when removal and replacement become necessary. Working with tools within the limited space available can result in damage to the relays or sockets. This damage may be in the form of latent defects which do not become apparent until the aircraft is in service and which, therefore, can have serious consequences. Even under the best circumstances stud and nut connections for plug-in components are laborious and time-consuming, both for installation and disassembly. Threaded connections also are subject to possible loosening under vibrational loads and in some instances nuts may not be properly tightened when the installation is made.
U.S. Pat. No. 3,790,915 provides a mounting arrangement that eliminates many of these problems, but which itself suffers from certain disadvantages. Spring tabs extend outwardly of the attaching unit and these are subject to being distorted or bent during handling, thus preventing proper attachment. It has been found that the attaching unit may sometimes be removed together with its socket, after removing the relay and this is undesirable since in many applications it is only the relay that need be removed.
Since relays of different sizes are often employed, the prior arrangement requires openings in the mounting member dimensioned for different sized relays, or might allow shifting of a smaller component in a larger opening, whereas it would be preferable to provide openings that would accept and firmly locate various sizes of components. Moreover, in mounting certain types of relays it is possible to cock the relay so that it is connected electrically without securely mounting it physically in the retaining arrangement of the prior patent.
The locking knob on the relay of the prior patent is not sealed against adverse environmental conditions to a satisfactory degree and some relays can be inadvertently mounted in reversed position.
Accordingly, it is an object of the present invention to provide a mounting arrangement that minimizes or eliminates above-mentioned problems.